A component in the turbine engine is the turbine wheel that extracts energy from the hot gas to deliver power. Traditionally the turbine wheel is made of two components, multiple blades and a disk. The blades are exposed to the hot gas stream to extract its energy and generate force to rotate the disk. The blades are commonly attached to the disk by an axially aligned, upside down, “Christmas tree” projection, or root, that fits in a mating, upside down “Christmas tree” cut-out in the disk. Other shaped mating projections and cut-outs are also known to mount turbine blades to turbine disk.
The turbine disk attaches to a shaft that may drive a compressor section that compresses air input to a burner for combustion therein, and a fan section to provide thrust for an aircraft or a generator to provide electrical power.
To keep the turbine blades axially aligned about the turbine disk during operation, a retention device is used to prevent the blades from being pushed out the disk cut-out. The retention device can have many different shapes depending on requirements but acts mainly as a lock to fix the blade in the disk.